Participants in a ‘White Lives Matter’ rally in Shelbyville, Tennessee, on 28 October. A woman has alleged that a group of white nationalists assaulted her after the march.
Photograph: Stephanie Keith/Reuters

A white woman in an interracial relationship alleged white nationalists attacked her and her partner after a “White Lives Matter” march in Tennessee on Saturday, according to a statement from the Nashville police department.

The “White Lives Matter” event, which was closely monitored by law enforcement, was raucous but non-violent, with marchers chanting, “Closed borders, white nation, now we start the deportation.”

Hundreds of energetic counter-protesters outnumbered the white nationalists, reportedly jeering at them and blasting songs to drown out racist speeches.

Nashville police said in a statement on Sunday that detectives were investigating the incident and had interviewed the alleged victim, whose name was not released.

The woman told police that a group of white men and women had entered a pub in Brentwood, a town south of Nashville, on Saturday night and sat behind the couple, a 30-year-old white woman and a 37-year-old black man.

A group member invited the woman to guess who they were. She responded “White Lives Matter”. Another member of the group told her, “That’s right,” and told her to join them and leave her boyfriend according to the statement.

After an argument unfolded inside, the woman told police that she went outside to de-escalate the situation. A woman in the group began to argue with her, and then a man allegedly struck her in the face with his fist, causing a cut above her eye, the woman told police. She refused medical treatment.

Police said they were seeking information on the suspect, described as a white man in his 30s wearing a black jacket and black jeans.

The unnamed woman shared a photograph of her bruised face with Fox 17 News Nashville, and said in a statement that the incident was “crazy” and that she has contacted a lawyer.

“We as Americans need to open our Eyes and come together stop this injustice and hate,” she said in a statement to Fox 17. “I am just shocked this happened and don’t understand why the business would serve these people when they have the right to refuse anyone.”

A similar sequence of events played out earlier this month in Gainesville, Florida, where a largely peaceful protest against a white nationalist event was followed by an alleged act of violence. Three white supremacists were arrested and charged with attempted murder for firing a gun at a group of protests who were waiting at a bus stop about a mile south of the event.

An organizer of the “White Lives Matter” rally wrote previously that the event was designed to help white nationalists move beyond the violence of August’s “Unite the Right” rally in Charlottesville, Virginia, where a car attack targeting counter-protesters left more than 19 people injured and one young white woman dead.